It is well known that light of different colors, particularly the primary colors red, blue and green, can be combined in various proportions to generate light having a wide variety of colors, including white light. It is also well known to use light emitting diodes (LEDs) for such a purpose. The intensity of light emitted by an LED can be varied by pulse width modulating (PWM) the power applied to the LED. The application of power to an LED or group of LEDs can be controlled by a PWM control signal generated by a microcontroller or the like. The microcontroller can be programmed to control multiple groups of LEDs, each generating light of a different primary color. By controlling the intensity of light generated by each color group of LEDs, the microcontroller can thus control the LEDs to generate a combined light of a specified color and intensity. The microcontroller can carry out such an operation in accordance with a variety of data inputs from sources such as a central controller, a user interface, a measurement device or the like.